In the related art, a combined structure of a liquid collector with a test tube is achieved by connecting a lower part of the liquid collector to the test tube in a manner of inserting.
Firstly, to inject liquid into a test tube, an injecting device is rigidly connected to the test tube and the rigid connection is of poor leakproofness and low stability, thus liquid will likely leak and the injecting device will be likely detached. As a result, cooperation of two persons is required for the injecting, causing complexity and inconvenience in operations.
Secondly, after the opening of the test tube is blocked by a tube plug, it is necessary to remove the tube plug to examine the substance or liquid in the test tube, causing redundant operation steps.
Thirdly, when the injecting device is withdrawn from the opening of the test tube after finishing injecting the liquid into the test tube, the liquid in the test tube is likely taken out from the test tube by the injecting device, thereby contaminating the outside of the test tube.
Fourthly, it is not possible to control the height of the injected liquid in the test tube when the liquid is being injected into the test tube, and the injecting is stopped only after the test tube is full of the injected liquid. In this case, inserting of a test strip or a testing sucker into the test tube easily causes overflowing of the liquid from the test tube, resulting in contamination.
Therefore, in the art, there is a need for a tube plug, which ensures the stable cooperation between the injecting device and the test tube, prevents liquid leak from the test tube, closes the opening of the test tube while liquid is being injected into the test tube, eliminates the contamination, and enables examination of the liquid in the test tube without removing the tube plug.